Spring strut support bearing

ABSTRACT

A spring strut support bearing, has a top bearing that can be affixed by its inner ring to the front end of an automobile, e.g. to the end of a piston rod of a shock absorber facing a vehicle body. The inner ring is surrounded by an outer ring with radial clearance; at least one elastic spring element made of rubber-elastic material is arranged in a gap formed by the clearance. The outer ring is disposed in a stationary manner with respect to the vehicle body; and only the component of the loading force of the shock absorber extending through the elastic spring element of the top bearing reaches the vehicle body. The inner ring has on each of its two end faces at least one elastically flexible stop buffer for limiting extreme deflection movements in moving direction of the shock absorber, the stop buffers each having the capability of being brought into contact with counter stop faces.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of U.S. patent application Ser. No.09/627,992, filed Jul. 28, 2000 now U.S. Pat. No. 6,666,311.

FIELD OF THE INVENTION

The invention relates to a spring strut support bearing.

BACKGROUND OF THE INVENTION

Spring strut support bearings (also known as suspension turret webs) aregenerally known and, for example, form a part of a front suspension in amotor vehicle.

SUMMARY OF THE INVENTION

The object of the present invention is to further develop a suspensionturret web in such a way that extreme deflections of the inner ring inthe direction of the introduced vibrations are limited in relation tothe outer ring of a top bearing which forms a component of the springstrut. A further object is that undesirably high shearing stresses inthe elastic spring element which connects the inner and outer rings ofthe top bearing be prevented, and that because of this, the suspensionturret web exhibits uniformly good working properties during a longerservice life.

To achieve the objective, a suspension turret web is provided whichincludes a top bearing that is able to be affixed by its inner ring tothe front end, the end of a piston rod of a shock absorber facing avehicle body. The inner ring is surrounded by an outer ring with radialclearance. At least one elastic spring element made of rubber-elasticmaterial is arranged in the gap formed by the clearance, and the outerring is disposed in a stationary manner with respect to the vehiclebody. The inner ring has on each of its two end faces at least oneelastically flexible stop buffer for limiting extreme deflectionmovements in the moving direction of the shock absorber, and the stopbuffers each have the capability of being brought into contact withcounter stop faces. The above-described embodiment ensures theprevention of undesirably high shearing stresses within the elasticspring element which reduce its service life, because the deflectionmovement of the inner ring relative to the outer ring is limited by theelastically flexible stop buffers. In this context, the counter stopfaces are fixedly joined to the vehicle body. Parts which are fixedlyjoined to the vehicle body, thus, for example, plates which are boltedor welded to the vehicle body, also belong to the vehicle body withinthe framework of the present invention. The stop buffers always contacttheir counter stop faces when low-frequency, large-amplitude vibrationsare introduced into the shock absorber, for example, when the wheel runsover the curb.

The top bearing can be produced simply and cost-effectively by formingthe stop buffers and the elastic spring element in one piece and of thesame material. The stop buffers and the elastic spring element areinjected in one shared operation into a tool cavity in which the innerring and the outer ring of the top bearing are already inserted.Following the injection of the rubber-elastic material, this materialhardens gradually and clutches permanently with claw-like fixation tothe surfaces of the inner and outer rings.

Another embodiment offers the possibility of producing the stop buffersseparately and connecting them frictionally and/or with form locking tothe respective end face of the inner ring. An advantage in this case isthat the stop buffers can be adapted particularly well to the respectiveconditions of the specific application, irrespective of the materialfrom which the elastic spring element is made. For example, the stopbuffers can be mounted with adhesive on the end faces of the inner ringor can have the ability to snap into undercut, e.g., dovetailedrecesses, of the inner ring.

A comparatively more durable, form-locking connection can be achieved inthat the inner ring has at least one opening extending essentially inthe axial direction from end face to end face, and the opening ispenetrated by material of the stop buffers. Such an embodiment is onlyuseful when the rubber-elastic material is injected into a tool cavityand subsequently vulcanized between the inner ring and outer ring.

Stop buffers made of a cellular polyurethane have particularlyadvantageous working properties. Compared to other materials, cellularpolyurethane has the advantage that the damping capacity increasesrelatively with the increase in amplitude, and the dynamic hardening isgenerally not so high compared to elastomers.

The stop buffers can be formed on each side of the inner ring by, ineach case, at least three lug cams uniformly distributed in thecircumferential direction. The form of the lug cams is preferably suchthat a progressively rising spring tension results as the springdeflection path increases. This ensures that the stop buffers contactthe counter stop faces gently at first, e.g., to prevent shaking andsharp noises, and a stronger bracing of the two parts against each otheronly results as the spring deflection path increases.

The outer ring can be stationary mounted in an essentially cup-shapedflange, the flange and the vehicle body being fixedly joined. Such anembodiment is advantageous with a view to producing suspension turretwebs in the unitized construction system. Variously configured flangesoffer the possibility of adapting the suspension turret web to therespective installation situation.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a cross-sectional view of a first embodiment of the invention;

FIGS. 2 and 3 are cross-sectional views of embodiments having differingstop buffers.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an exemplary embodiment of a spring strut support bearing,which has a top bearing 1 composed of an inner ring 2 and an outer ring6 surrounding inner ring 2 with radial clearance. The inner ring 2 andouter ring 6 are joined by elastic spring element 8 arranged within gap7.

In this exemplary embodiment, stop buffers 11, 12, which are arranged onend faces 9, 10 of inner ring 2, are configured integrally andcontinuously with elastic spring element 8. An embodiment deviating fromthis, which can be used here as well, is shown in FIGS. 2 and 3,respectively.

Outer ring 6 is pressed into a cup-shaped flange 19 that is immovablyjoined to vehicle body 3, e.g., by a screw coupling or welding.

FIGS. 2 and 3 each show a cutaway portion from top bearing 1 of FIG. 1,stop buffers 11, 12 being affixed to inner ring 2 differently than inthe embodiment of FIG. 1.

In FIG. 2, stop buffers 11, 12 are produced separately and joined torespective end faces 9, 10 of inner ring 2 with form locking.Additionally or alternatively, it is possible to provide a frictionalconnection, e.g., by cementing.

In this embodiment, stop buffers 11, 12 are snapped into undercutrecesses 30, 31 of respective end faces 9, 10 of inner ring 2, recesses30, 31 each being dovetailed.

In FIG. 3, inner ring 2 has a plurality of openings 32 that extendessentially in the axial direction from end face 9 to end face 10 andare distributed in the circumferential direction, openings 32 beingpenetrated by the elastomeric material of stop buffers 11, 12.Particularly good durability is achieved in this manner.

Separately formed stop buffers 11, 12 are preferably made of a cellularpolyurethane.

In response to extreme deflection movements of inner ring 2 in movingdirection 13 relative to outer ring 6, stop buffers 11, 12 come incontact with counter stop faces 14, 15, counter stop face 15 beingformed by bottom 20 of flange 19. Upper end-face stop buffer 11 contactscounter stop face 14 which is designed as a cover and forms a componentof vehicle body 3.

1. A spring strut support bearing, comprising: a top bearing having aninner ring by way of which the top bearing can be affixed to the end ofa piston rod of a shock absorber connected to a vehicle body; an outerring surrounding the inner ring with radial clearance defining a gaptherebetween, the outer ring being stationary with respect to thevehicle body; at least one elastic spring element made of rubber-elasticmaterial located in the gap formed by the clearance; wherein the innerring has two end faces, on each of which has at least one elasticallyflexible cellular polyurethane annular stop buffer independent from saidat least one elastic spring element, said stop buffers being snap-fitinto recesses formed in said end faces and limiting extreme deflectionmovements along a deflection direction defined by the motion of a shockabsorber, each of the stop buffers having the capability of beingbrought into contact with counter stop faces, a central hole of eachannular stop buffer arranged to receive the piston rod therethrough, thestop buffer of one end face substantially symmetric to the stop bufferof the other end face about a middle plane between the one end face andthe other end face; and the outer ring is fixedly mounted in anessentially cup-shaped flange, and the flange is fixedly joined to thevehicle body.
 2. The spring strut support bearing according to claim 1,wherein said generally cylindrical portion is joined to a bottom surfaceof the vehicle body.
 3. The spring strut support bearing according toclaim 1, wherein the recesses are dovetailed.
 4. A spring strut supportbearing, comprising: a top bearing having an inner ring adapted to affixthe top bearing to the end of a piston rod of a shock absorber connectedto a vehicle body; an outer ring surrounding the inner ring with radialclearance defining a gap therebetween, the outer ring stationary withrespect to the vehicle body; at least one elastic spring element made ofrubber-elastic material located in the gap formed by the clearance;wherein the inner ring has two end faces with a plurality of openingsthat extend axially between the end faces, on each of which has at leastone elastically flexible cellular polyurethane annular stop bufferindependent from said elastic spring element, said stop buffers beingdisposed in said openings and adapted to limit extreme deflectionmovements along a deflection direction defined by the motion of a shockabsorber, each of the stop buffers adapted to be brought into contactwith counter stop faces, a central hole of each annular stop bufferarranged to receive the piston rod therethrough, the stop buffer of oneend face substantially symmetric to the stop buffer of the other endface about a middle plane between the one end face and the other endface; and the outer ring is press fit in a generally cylindrical portionjoined to a bottom surface of the vehicle body.